The present invention generally relates to a radial artery pressure pulse wave transducer for sensing a change in the pressure of the blood vessels in vivo, and converting the sensed result into an electrical signal to detect a pressure pulse wave. Specifically, the invention relates to a device for equal pressure distribution at given sensing points by using a pneumatic system for improved tightness and simultaneous conversion of force transferred through an air medium into an electrical signal to detect the pressure pulse wave.
Blood pressure is measured to diagnose human body condition so that a medical practitioner can determine whether or not an individual has a cardiovascular-related disease.
There is a conventional blood pressure measuring system which employs a method by which an electronic sensor such as a piezoelectric device, etc., directly contacts the human body to measure a change in the pressure within the blood vessel. This conventional blood pressure measuring system uses a single measuring point. Recently, several pulse transducers using the three-point measurement system have been developed and utilized in the field of Oriental medicine. However, none of the devices using the three-point measurement system is reliable because there have been mechanical problems due to the non-uniform measuring conditions at the three points.
It is therefore the object of the present invention to provide a pressure pulse wave transducer that assures an accurate 3-point measurement method by using a pneumatic system that applies a uniform pressure at a given sensing point.
To achieve this object, the present invention provides a pressure pulse wave transducer for detecting pulse waves at three points in a person""s wrist comprising: a body having a space for longitudinally accepting a wrist; three depressing frames movably installed for contacting the wrist; a pressure means uniformly pressing the depressing frames; three measuring cavities, each installed within the depressing frames and filled with a constant compressed air; contactors which are inserted into the depressing frames and which are attached to the measuring cavities; differential pressure sensors, each connected to ports at one side of the measuring cavities for detecting a pressure change in the measuring cavities; and a reference cavity connected to ports at one side of the differential pressure sensors, said reference cavity having constant pressure, where the contactors apply the same pressure to each of three points, and the pressure sensors measure the pressure difference between the reference cavity and the measuring cavities simultaneously to detect the pulse wave of the radial artery.